Steel C20E2C +U (Hot rolled)
Finish state · default condition
EN C20E2C
Cheapest stock condition for bar that will be machined, then carburized and hardened.
Values for the +U condition
Other C20E2C tempers and conditions
C20E2C is listed in 6 conditions; see the grade overview at C20E2C.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Pick when maximum cold formability is needed before drawing, cold heading or extrusion. | 235 | 390 | 32 | 115 HB | — |
+UDefaultThis page Hot rolled | Cheapest stock condition for bar that will be machined, then carburized and hardened. | 250 | 420 | 28 | 116 HB | — |
Normalized | Pick to refine grain and give uniform ferrite-pearlite before machining/carburizing of forged parts. | 285 | 440 | 27 | 126 HB | — |
Spheroidize annealed then cold drawn | Standard cold-heading wire/bar condition: bright tolerance plus retained ductility for upsetting. | 380 | 470 | 18 | 132 HB | — |
Hot rolled and cold drawn | Pick for close-tolerance bright bar with higher strength and better chip control on automatics. | 420 | 520 | 14 | 143 HB | — |
Carburized and hardened | Final service condition: hard wear-resistant case (0.3–1.2 mm) over a tough low-strength core. | 420 | 620 | 12 | 60 HRC | — |
What is C20E2C +U?
C20E2C +U is C20E2C supplied in the +U condition — cheapest stock condition for bar that will be machined, then carburized and hardened. C20E2C +U has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 94% of steel grades. Elongation at break is 28% and the elastic modulus is 207 GPa (30 Msi). C20E2C +U has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Advantages
- Readily welded — 95/100, better than 97% of steel grades
- Conducts heat well — 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades
- Tough — resists crack growth — 140 MPa·√m (127.4 ksi·√in), better than 94% of steel grades
- High electrical conductivity — 10.8 % IACS, better than 94% of steel grades
- Forms and bends easily — 82/100, better than 94% of steel grades
Limitations
- Low strength — 250 MPa (36.3 ksi), worse than 94% of steel grades
C20E2C +U properties
Typical room-temperature values for C20E2C +U; 14 are specific to this condition. Other listed values are C20E2C reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
C20E2C +U has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
C20E2C +U has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 94% of steel grades. Elongation at break is 28% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
C20E2C +U is rated for continuous service to 400°C (752 °F). It conducts heat at 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
C20E2C +U conducts electricity at 10.8 % IACS, better than 94% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of C20E2C +U takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability6
C20E2C +U's machinability is good (58/100, better than 75% of steel grades); weldability excellent (95/100); formability very good (82/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C20E2C +U
Is C20E2C easy to machine?
Machines easily but is gummy when annealed — use sharp positive-rake tools, high speed and generous coolant; normalized or cold-drawn stock gives the cleanest chips and best finish.
Can C20E2C be welded?
Excellent weldability by all arc, resistance and gas processes with no preheat in thin sections; do not weld after carburizing.
Can C20E2C be formed, bent or molded?
Very good cold formability — deep drawing, bending and cold heading are routine in +AC or +AC+C; hot forge 1100–1200 °C, then normalize.
What surface finishes work on C20E2C?
No anodizing; protect by zinc/nickel plating, phosphate + oil, black oxide or paint — bare surfaces rust quickly, and carburized parts should be plated only with low-hydrogen processes plus baking.
C20E2C chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Crestricted range for controlled hardenability | 0.17 – 0.23 | 0.2 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.6 – 0.9 | 0.75 |
| P | ≤ 0.03 | — |
| Slow-S variants used for cold heading | ≤ 0.04 | 0.02 |
| Crresidual | ≤ 0.4 | 0.15 |
| Niresidual | ≤ 0.4 | 0.15 |
| Curesidual | ≤ 0.4 | 0.2 |
| Moresidual; Cr+Ni+Mo commonly limited to ≤0.63 | ≤ 0.1 | 0.03 |
| Fe | balance | — |
C20E2C +U — frequently asked
What is C20E2C +U used for?
C20E2C +U is typically used for gears, cams, pins and case-hardened fasteners. In short: controlled-hardenability carburizing grade; cold-heading quality wire and bar; hard case, ductile core.
What is the yield strength of C20E2C +U?
C20E2C +U has a typical yield strength of 250 MPa (36.3 ksi) and a tensile strength of 420 MPa (60.9 ksi) — weaker than 94% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is C20E2C +U easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Machines easily but is gummy when annealed — use sharp positive-rake tools, high speed and generous coolant; normalized or cold-drawn stock gives the cleanest chips and best finish.
Can C20E2C +U be welded?
Yes — weldability is rated excellent (95/100). Excellent weldability by all arc, resistance and gas processes with no preheat in thin sections; do not weld after carburizing.
What surface finishes work on C20E2C +U?
No anodizing; protect by zinc/nickel plating, phosphate + oil, black oxide or paint — bare surfaces rust quickly, and carburized parts should be plated only with low-hydrogen processes plus baking.
Can C20E2C +U be formed, bent or molded?
Very good cold formability — deep drawing, bending and cold heading are routine in +AC or +AC+C; hot forge 1100–1200 °C, then normalize.
What is the maximum service temperature of C20E2C +U?
C20E2C +U is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C20E2C +U and C20E2C-CH?
+U is the default condition — cheapest stock condition for bar that will be machined, then carburized and hardened. CH: final service condition: hard wear-resistant case (0.3–1.2 mm) over a tough low-strength core. Yield strength is 250 MPa in +U versus 420 MPa in CH.
Sources
- EN 10084 — Case hardening steels: technical delivery conditions — CEN (2008)
- EN 10263-3/-4 — Steel rod, bars and wire for cold heading and cold extrusion — CEN (2017)
- GB/T 699 — Quality carbon structural steels (20 ) — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4A/4D — Steel Heat Treating / Carburizing — ASM International (2014)
- ASM Handbook Vol.16 — Machining (machinability ratings) — ASM International (1989)
- Mysteel / SMM · (2025)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.